Compensating bridge for stringed musical instruments



Aug. 10 1926.

P. MARINO COIFBNSATING BRIDGE FOR STRINGS!) IUSICAL IN STRUIBNTS Filed Oct, 10. 1924 Patented Aug. 10, 1926.

rasanennmsnnro, or HARRISON, new JERSEY.

commmnm BRIDGE FOB STRINGED MUSICALINSTBUMENTS,

Application filed October 10, 1924. Serial-N0. 742,908.

'Flri's invention relatesto improvements in bridges for stringed musioalinstruments.

llt is a well known fact that regardless of careful tuning of-astringed musical instrua meant, one or more of the strings are liable to giveofiover-tones, when struck, due to ai'sllghtdistortion'in the sound board or head of the instimment or any. inequalities in filir' bridgesnpporting the strings or in the stringsithemselves The bridge of an ardi'miy stringed mnsioal instrument coma solid or one-piece bodyv "having string-remitting notolies in its ridge, and 'Wlierisuchfabridgeiis accurately positioned with" all} points offiits ridge equidistantly spaced mm; the not of the instrument, overtones are less eliminated and the" strings will give off true tones when vibrated Hbwe'ver ariyslightdeviation of thellritlge from such jnstment isiliable to afleet the,qua 1ity oi'the tones from one or moreof the strings and the-present invention, therefcre, has asiits object" to provide a bridge-of eachcoristmc-tion that; by a s'iin e adfustinent, any factors tending to pro lice oventonesfwhen the strings are vibrated; may-be compensated for, and: the quality ofthe tones gieatly improved;

Another objeet'foftlie invention is to provide a bridge fiirstringed musical instruments embodying anjndividual rest for each strin ,andrneanstor independently and indjvi any adiusung said-'rests;,so that the resting points of the stringsmaybe varied,

enalilingthe player of the instrument to readilfvwcompensate forany factors Which mig'litfiend to affect the proper unirm vibration of any one or more of'the several'strings.

In the accompanying drawings: Figure 1"; is a perspective'view ofthe bridge embodying the invention; applied to a guitar, only so much offthe instrument as is necemary to illustrate the application of the invention, being shown in-the figure.

Figure 2 is a plan view of" the bridge, the casing thereof being shown partly in section.

Fi re 3 is a vertical front to roan sec tibna view taken substantially on the line W30??? urea, looking-in the direction: in

Figure 4 is a rear elevation ofthe bridge, the-casing being removed.

The bridge embodying the invention comprises a base platewhich is indicated r by: the: numeral 1 and which may be of; any desired mar inal. contour and dimensions and is provi ed upon its upper sidewith two upright bearing members indicated .one 6.9 by the numeral 2 and theother by the 1111- moral {3,the members being integrally formed with thei plate 1, or in the nature of small rectangular plates or: strips secured'at their lower edges to the saidbase plate. The said 5 bearing members 2 and 3 extend-in parallel planes transversely of the upper side of the plate 1 and they are formed; at, intervals in their length respectively, with openings r and: 5, corresponding ones of the; openings 7 1n the two members being in; ahnement, as

clearly shoWn-in-Figure 350i the drawings. In t the illustrated embodimentof the invention, sleeves 6 are rotatably mounted in the openings 4 and?) and; each sleeve; is formed with a threaded socket? opening through the forward end of the sleeve; the sleeve at its rear end" being; reduced and squared tolprovide a portion 8' to which} is fitted and suitably secured-a Worm: gear i i-.80 dioated by the numeral 9.- By referenceto Figure 2 of the drawings, it will b observed that alternate ones of the sleeves 6 are of alength to extend through'both of the members: 2 and, 3, Whereas the othersleeves extend only through the v member-2, that the worm gears or p n ons: upon the rear ends of the first. mentioned'sleeves are located in rear of the member 3, where-- as the. pinions upon the rear ends of the other sleeves are locatedinrear of the memher 2, the arrangement beingisuch as toeffeet. economy in spat-in and permit of relative close arrangement of the sleeves to one another. The numeral l0v indicates small 'wvorm shafts which are stepped at. their lowerends, as at '11. in openings 12in the base plate 1, certain of the worms being located in rear of-thebearing member Qand others in rear; of the bearing member 31 The upper ends of the WOIHI shafts. or s 'indles arereduoed to provide small cylinrical portions 13' which are received in bearing openings: .14 formed in bearing plates 15 which are mounted upon the upper portions of the bearing members 2 and S, and the worm spindles are so arranged that each of the spindles will mesh with an individual one of the worm pinions 9. The upper extremity of the portion 13 of each worm spindle is reduced and squared as at 16 for the application thereto of a suitable lcey not shown) whereby the spindle may be rotated so as to impart rotary motion to the respective sleeve 6 "For a purpose to be presently explained.

A casing, indicated in general by the numeral 1?, is preferably provided for covering and concealing the gearing and to provide against contact of the wrist or sleeve of the player therewith, and this casing comprises a rounded top 18 having openings 19 formed therein and located immediately above the squared extremities 16 01' the worm spindles to permit of insertion oi the key referred to above. The casing further includes ends 20 which extend downwardly at opposite ends of the bearing members 2 and 3 and from the member 2 rearwardly to the rear wall of the casing which is indicated by the numeral 21 and which depends in rear of the pinions 9, as best shown in Figure 3 of the drawings. The casing has a short depending front wall 22 which is slotted as at 23. to accommodate the strings of the instrument, indicated by the letter S, and the wall 21 of said casing is formed vith slots 2i for a like purpose, the said slots opening through the lower edge of the said wall. In like manner, the bearing members 2 and 3 are formed with alined openings 25 through which the strings S are passed, the strings, of course, extending above the pinions 9 and their respective worm spindles so as not to come in contact therewith. It is preferable that the ends of the bearing member 3 be provided wit-h ears 26 having threaded openings to receive screws 27 which are fitted through the end walls 20 of the casing 17, so that by removing these screws, the casing may be bodily removed and access had to the adjusting mechanism of the bridge.

In order that the length of the portion of each individual string which extends between the nut of the instrument and the bridge may be varied to compensate for factors which. if an ordinary bridge were used, would cause over-tones, the bridge embodying the present invention includes a plurality oi individual rest members for the strings. indicated in general by the numeral 28. Each of these rest members comprises a preferably rectangular head 29 having a threaded shank 3O fitted through a threaded opening therein and fitted at its rear end into the socket T oi": the respective sleeve 6. The ver ical sides at the several rest members are disposed relatively close to one another throughout the series, and their lower sides rest squarely upon the upper side ol the base plate 1, as clearly shown in Figure 3 ot' the drawings. The upper side of each head 29 is formed with a shallow notch 31 to accommodate a respective string, and it will be observed by reference to the several figures that the strings are led from the tail piece of the instrument, through the slots 2%, openings 25, and. slots 2?, to the individual rests 28, where they are seated in their respective notches 31. In practice, the rest members will be so adjusted as to extend transversely in alinement but should it be found that any one or more of the strings. when vibrated. gives an over-tone, this may be remedied by applying the key to the respective worm spindle l3 and rotating the worm to ell'eet rotation of the respective sleeve 6 and there by forwardly or rearwardly shift the head 29 and thus effect a lengthening or shortening of the portion of the string which extends between the nut and the respective rest member.

\Vhile I have illustrated and described an arrangement of gearing for the purpose of eiiecting adjustment of the string rests, it will be evident that various means might be employed for this purpose without departing from the spirit of the invention, the invention contemplating, broadly, the provision of a bridge for stringed musical instruments embodying a plurality of independently adjustable string rests and any suitable means i'or adjusting the same.

It will be evident that inasmuch as the heads 29 are threaded to the stems 30, any one of the heads may be removed and re placed by a new one, in the event such replacement becomes necessary, or in the event of loss of any one of the heads.

Having thus described the invention, what I claim is:

1. A bridge for stringed musical instruments comprising a base to be mounted upon the instrument, a housing carried by said base, sleeves rotatably mounted in said housing and projecting forwardly from the housing, threaded stems extending from the forward ends of said sleeves and rotating with the sleeves, string rests slidable along said base and having threaded openings receiving said stems to cause the string rests to be moved longitudinally upon said base when said sleeves and stems are rotated, and means in said housing to individually rotate said sleeves and through the medium of said stems effect individual adjustment of said string rests.

2. A bridge for stringed musical instruments comprising a base to be mounted upon the instrument, a housing extending transversely across the rear portion of said base, string rests upon said base in front of said housing and movable towards and away tilt) from the housing, adjusting stems for said string rests extendin into said housin and having their outer en portions engage said string rests, and means in said housing engaged with said stems to impart movement to said stems for individual adjustment of said stems.

3. A bridge for stringed musical instruments comprising a base to be mounted upon the instrument, a housing extending transversely across the rear portion of said base, stri rests upon said base in front of said housing and movable towards and away from the housing, adjusting stems for said string rests extending into said housing and rotatable therein, operating shafts rotatably mounted in said housing and disposed vertically therein, said housing having its upper wall provided with openings permitting access to the upper ends of the shafts for rotation thereof, and means for transmitting rowith tary movement from said shafts to said stems whereby said stems may be individually rotated to effect adjustment of their cooperating string rests.

4. A bridge for stringed musical instruments comprising a base to be secured upon the instrument, a housing carried by the rear portion of said base, string rests slidable upon the forward portion of said base towards and away from the housing, stems I rotatably mounted in said housing and projecting forwardly from the housing and having threaded forward portions screwed through threaded openings in said string rests to impart sliding movement thereto when the stems are rotated, and means for rotating said stems to'eflect individual adjustment of the string rests engaged thereby. In testimony whereof I affix my signature.

PASQUALE MARINO. [Ls] 

